For storage operating control methods, roughly dividing, there are two main ways. One is an “In band method”, in which storage operating data, such as, structure information of the storage, maintenance information, etc., is operated, thereby to conduct the operating control, by using the same interface, through which a host computer performs read-out/write-in of data on the storage. The other one is an “Out of band method”, in which the operating control is carried out through an interface, which is perfectly different, physically and theoretically, from the interface, through which the read-out/write-in on the storage is conducted from the host computer.
In the former, there is an advantage that the storage operating control can be linked with an application(s) of the host computer easily, while in the latter, there are advantages, that the operating control does not depend upon the operating system on the host computer, and that it is possible to conduct the storage operating control at any time without preparation of an exclusive storage operating agent on the host computer. Further, in the latter, there is an advantage for the host computer that a system can be assembled with no attention to or awareness of the storage operating control.
FIG. 2 shows one of the conventional methods, which is called by the “In band method”. The host computer 101 and an external storage device 108 are connected to each other through a Fiber Channel 103, and through this interface are transferred storage data 105 and storage operating data 107. Also, in the host computer 101 is prepared a storage operating agent 201. The storage operating of the external storage device 108 carries out the control from a storage operating terminal 202 through the storage operating agent 201 on the host computer 101. The storage operating terminal 202 and the host computer 101 are connected through a LAN, in which TCP/IP 104 is used as protocol thereof.
In this method, since an application 102 and the storage operating agent 201 are operating on the same host computer 101, there is an advantage that the storage operating control can be performed in linking or cooperation with each other, depending upon the convenience of the application 201. On the contrary, it is necessary to introduce the storage operating agent 201 into each the host computer 101, therefore the storage operating agents operable upon the various operating systems of the host computers 101 must be prepared and further installed in advance, respectively. Also, the storage operating control is unavailable when the host computer 101 is not initialized or started.
FIG. 3 shows one of the conventional methods, which is called by the “Out of band method”. In the external device 108 are stored storage data 105 and storage operating data 107, and it is characterized that each communicates with an outside through the respective interfaces. The storage data 105 is connected with the host computer 101 through the Fiber Channel 103. The storage operating terminal 202 is connected through the LAN to a service processor 106 for managing the storage operating data 107, thereby performing the communication therebetween.
With this method, there is an advantage that the operating control of the storage can be performed without an attention nor consciousness of the host computer. Accordingly, no such the storage operating agent 201 is necessary, as in the “In band method”, and the storage operation does not depend upon a platform of the host computer. However, since the storage operating terminal 202 and the host computer 101 use the interfaces, being totally different from each other, they are independent, therefore it is impossible to link or cooperate the application on the host computer 101 with the storage operation.